The London System is an opening system in chess where White opens with 1.d4 and develops the dark-squared bishop to f4, then supports the d4-pawn with pawns on e3 and c3.

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The London System is an opening system in chess where White opens with 1.d4 and develops the dark-squared bishop to f4, then supports the d4-pawn with pawns on e3 and c3.